Generally, the crown of sugar beet has not been used for the extraction in beet sugar factory in the world. While, we found the sugar beet sown in summer in the warmer region of Japan has remarkable weight of crown and it has high in content of sucrose. Therefore, in order to know the chemical quality of sugar beet crown and influence topping position in crown upon the quality of sugar beet, we have determined the content of sucrose, reducing sugar, raffinose, harmful nitrogen, betaine and blue number. The sugar yield are calculated by the methods of Stammer and Ludecke. The results are summerized as follows: 1. It has not so difference in the content of sugar, nitrogeneous compounds and soluble ash between crown and root of sugar beet as others harvested in Hokkaido, U. S. A., or Europe. Comparatively speaking, within the parts of crown, basal part of green leaves is poor in quality and part of dead leaves has high in quality. The content of sucrose and other constituents except reducing sugar of the latter part are near to the root of sugar beet. 2. The influence of topping to the chemical quality of sugar beet, comparing with topping at the head line of the dead leaves and topping under 1-2 cm at this line, the latter is higher in quality and very similar to the correct topping. The calculated sugar yield are increased 25-30 per cent as compared with correct topping in the two formulas.